Vulnerability Monitor

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CVE-2020-13943

If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 4.3, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts limited data confidentiality, for affected systems. Impacting 4 products from apache, from debian, from oracle and 1 other, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2020-10-12T14:15:12.183

Last Modified

2024-11-21T05:02:11.967

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 4.3 (MEDIUM)

CVSSv2 Vector

AV:N/AC:L/Au:S/C:P/I:N/A:N

Access Vector: NETWORK
Access Complexity: LOW
Authentication: SINGLE
Confidentiality Impact: PARTIAL
Integrity Impact: NONE
Availability Impact: NONE

Exploitability Score

8.0

Impact Score

2.9

Weaknesses

Type: Primary
NVD-CWE-noinfo

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	apache	tomcat	8.5.0	Yes
Application	apache	tomcat	8.5.1	Yes
Application	apache	tomcat	8.5.2	Yes
Application	apache	tomcat	8.5.3	Yes
Application	apache	tomcat	8.5.4	Yes
Application	apache	tomcat	8.5.5	Yes
Application	apache	tomcat	8.5.6	Yes
Application	apache	tomcat	8.5.7	Yes
Application	apache	tomcat	8.5.8	Yes
Application	apache	tomcat	8.5.9	Yes
Application	apache	tomcat	8.5.10	Yes
Application	apache	tomcat	8.5.11	Yes
Application	apache	tomcat	8.5.12	Yes
Application	apache	tomcat	8.5.13	Yes
Application	apache	tomcat	8.5.14	Yes
Application	apache	tomcat	8.5.15	Yes
Application	apache	tomcat	8.5.16	Yes
Application	apache	tomcat	8.5.17	Yes
Application	apache	tomcat	8.5.18	Yes
Application	apache	tomcat	8.5.19	Yes
Application	apache	tomcat	8.5.20	Yes
Application	apache	tomcat	8.5.21	Yes
Application	apache	tomcat	8.5.22	Yes
Application	apache	tomcat	8.5.23	Yes
Application	apache	tomcat	8.5.24	Yes
Application	apache	tomcat	8.5.25	Yes
Application	apache	tomcat	8.5.26	Yes
Application	apache	tomcat	8.5.27	Yes
Application	apache	tomcat	8.5.28	Yes
Application	apache	tomcat	8.5.29	Yes
Application	apache	tomcat	8.5.30	Yes
Application	apache	tomcat	8.5.31	Yes
Application	apache	tomcat	8.5.32	Yes
Application	apache	tomcat	8.5.33	Yes
Application	apache	tomcat	8.5.34	Yes
Application	apache	tomcat	8.5.35	Yes
Application	apache	tomcat	8.5.36	Yes
Application	apache	tomcat	8.5.37	Yes
Application	apache	tomcat	8.5.38	Yes
Application	apache	tomcat	8.5.39	Yes
Application	apache	tomcat	8.5.40	Yes
Application	apache	tomcat	8.5.41	Yes
Application	apache	tomcat	8.5.42	Yes
Application	apache	tomcat	8.5.43	Yes
Application	apache	tomcat	8.5.44	Yes
Application	apache	tomcat	8.5.45	Yes
Application	apache	tomcat	8.5.46	Yes
Application	apache	tomcat	8.5.47	Yes
Application	apache	tomcat	8.5.48	Yes
Application	apache	tomcat	8.5.49	Yes
Application	apache	tomcat	8.5.50	Yes
Application	apache	tomcat	8.5.51	Yes
Application	apache	tomcat	8.5.52	Yes
Application	apache	tomcat	8.5.53	Yes
Application	apache	tomcat	8.5.54	Yes
Application	apache	tomcat	8.5.55	Yes
Application	apache	tomcat	8.5.56	Yes
Application	apache	tomcat	8.5.57	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.0	Yes
Application	apache	tomcat	9.0.1	Yes
Application	apache	tomcat	9.0.2	Yes
Application	apache	tomcat	9.0.3	Yes
Application	apache	tomcat	9.0.4	Yes
Application	apache	tomcat	9.0.5	Yes
Application	apache	tomcat	9.0.6	Yes
Application	apache	tomcat	9.0.7	Yes
Application	apache	tomcat	9.0.8	Yes
Application	apache	tomcat	9.0.9	Yes
Application	apache	tomcat	9.0.10	Yes
Application	apache	tomcat	9.0.11	Yes
Application	apache	tomcat	9.0.12	Yes
Application	apache	tomcat	9.0.13	Yes
Application	apache	tomcat	9.0.14	Yes
Application	apache	tomcat	9.0.15	Yes
Application	apache	tomcat	9.0.16	Yes
Application	apache	tomcat	9.0.17	Yes
Application	apache	tomcat	9.0.18	Yes
Application	apache	tomcat	9.0.19	Yes
Application	apache	tomcat	9.0.20	Yes
Application	apache	tomcat	9.0.21	Yes
Application	apache	tomcat	9.0.22	Yes
Application	apache	tomcat	9.0.23	Yes
Application	apache	tomcat	9.0.24	Yes
Application	apache	tomcat	9.0.25	Yes
Application	apache	tomcat	9.0.26	Yes
Application	apache	tomcat	9.0.27	Yes
Application	apache	tomcat	9.0.28	Yes
Application	apache	tomcat	9.0.29	Yes
Application	apache	tomcat	9.0.30	Yes
Application	apache	tomcat	9.0.31	Yes
Application	apache	tomcat	9.0.32	Yes
Application	apache	tomcat	9.0.33	Yes
Application	apache	tomcat	9.0.34	Yes
Application	apache	tomcat	9.0.35	Yes
Application	apache	tomcat	9.0.36	Yes
Application	apache	tomcat	9.0.37	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Application	apache	tomcat	10.0.0	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	debian	debian_linux	10.0	Yes
Application	oracle	instantis_enterprisetrack	17.1	Yes
Application	oracle	instantis_enterprisetrack	17.2	Yes
Application	oracle	instantis_enterprisetrack	17.3	Yes
Application	oracle	sd-wan_edge	9.0	Yes

References

http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html Mailing List, Third Party Advisory ([email protected])
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html Broken Link ([email protected])
https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html Third Party Advisory ([email protected])
https://security.netapp.com/advisory/ntap-20201016-0007/ Third Party Advisory ([email protected])
https://www.debian.org/security/2021/dsa-4835 Third Party Advisory ([email protected])
https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory ([email protected])
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html Broken Link (af854a3a-2127-422b-91ae-364da2661108)
https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://security.netapp.com/advisory/ntap-20201016-0007/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.debian.org/security/2021/dsa-4835 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For apache's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.